11-09-2013, 04:04 PM
Integer Wavelet Transform based Steganographic Method using OPA Algorithm
Integer Wavelet Transform .pdf (Size: 151.3 KB / Downloads: 30)
Abstract
This paper deal with secret communication in open
environment like internet .Steganography provides to hide the secret
information and make communication undetectable. Steganography
is used to hide the secret information so that no one can sense the
information. Steganographic method has many challenges such as
high hiding capacity and imperceptibility. In existing paper have
some problems like less robust and low hiding capacity. so in this
paper I use integer wavelet transform(IWT) for increasing hiding
capacity and Optimum pixel adjustment algorithm(OPA) for
enhancing the image quality use MATLAB to implement my paper,
because which has many inbuilt functions and easy to use.
INTRODUCTION
Steganography is the modern art and science of writing
hidden messages in such a way that no one, apart from the
sender and intended recipient, suspects the existence of the
message, a form of security. The word Steganography was
derived from two Greek words that mean "covered writing"
from the Greek words steganos
meaning "covered or
protected", and graphic meaning "writing". The first recorded
use of the term was in 1499.The advantage of Steganography,
over cryptography alone, is that message do not attract
attention to themselves. Plainly visible encrypted messages no
matter how unbreakable will arouse suspicion, and may in
themselves be incriminating in countries where encryption is
illegal. Therefore, whereas cryptography protects the contents
of a message, Steganography can be said to protect both
messages and communicating parties
INTEGER WAVELET TRANSFORM
Wavelet domain allows us to hide data in regions that the
human visual system (HVS) is less sensitive to, such as the
high resolution bands (HL, LH and HH), Hiding data in these
regions allow us to maximize the robustness while managing
good visual quality. Integer wavelet transform make an integer
data set into another integer data set. In discrete wavelet
transform, the used wavelet filters have floating point
coefficients so that when we hide data in their coefficients any
truncations of the floating point values of the pixels that
should be integers may make the loss of the hidden
information which may lead to the failure of the data hiding
system [9]. To avoid problems of floating point precision of
the wavelet filters when the input data is integer as in digital
images.
The Extraction Algorithm
MATLAB is a numerical computing environment and
fourth-generation programming language. Created by Math
Works, MATLAB permits matrix manipulations, plotting of
functions and data, implementation of algorithms, creation of
user interfaces, and interfacing with programs written in other
languages, including C, C++, Java, and Fortran.
Although MATLAB is intended primarily for numerical
computing, an optional toolbox uses the MuPAD symbolic
engine, allowing access to symbolic computing capabilities.
An additional package, Simulink, adds graphical multi-domain
simulation and Model-Based Design for dynamic and
embedded systems.
CONCLUSIONS
In this paper i proposed a data hiding scheme that hides data
into the integer wavelet coefficients of an image. The system
combines an integer wavelet transform and the optimum pixel
adjustment algorithm to maximize the hiding capacity of the
system compared to other systems. The proposed system
embeds secret information in a random order using a secret
key only known to both sender and receiver. is an adaptive
system which embeds different number of bits in each wavelet
coefficicient according to a hiding capacity function in order
to increase the hiding capacity without sacrificing the visual
quality of resulting stego image. The proposed system also
reduces the difference between original coefficients values and
modified values by using the optimum pixel adjustment
algorithm.